* refactor: options and sample configurations
* chore: newline at end of file
* chore: format code
* chore: remove comment and set sample configurations to default values
* chore: use single quoted string in sample configuration files
* feat: frontend instance
* no need to carry column length in `Column` proto
* add more tests
* rebase develop
* create a new variant with already provisioned RecordBatches in Output
* resolve code review comments
* new frontend instance does not connect datanode grpc
* add more tests
* add more tests
* rebase develop
Co-authored-by: luofucong <luofucong@greptime.com>